// yield/queue/blocking_concurrent_queue.hpp

// Copyright (c) 2011 Minor Gordon
// All rights reserved

// This source file is part of the Yield project.

// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// * Neither the name of the Yield project nor the
// names of its contributors may be used to endorse or promote products
// derived from this software without specific prior written permission.

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL Minor Gordon BE LIABLE FOR ANY DIRECT,
// INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
// THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#ifndef _YIELD_QUEUE_BLOCKING_CONCURRENT_QUEUE_HPP_
#define _YIELD_QUEUE_BLOCKING_CONCURRENT_QUEUE_HPP_

#include "yield/thread/mutex.hpp"

#include <queue>

namespace yield {
namespace queue {
template <class ElementType>
class BlockingConcurrentQueue : private std::queue<ElementType*> {
public:
  bool enqueue(ElementType& element) {
    mutex.lock();
    std::queue<ElementType*>::push(&element);
    mutex.unlock();
    return true;
  }

  ElementType* trydequeue() {
    mutex.lock();
    if (!std::queue<ElementType*>::empty()) {
      ElementType* element = std::queue<ElementType*>::front();
      std::queue<ElementType*>::pop();
      mutex.unlock();
      return element;
    } else {
      mutex.unlock();
      return NULL;
    }
  }

private:
  yield::thread::Mutex mutex;
};
}
}

#endif
